In a conventional structure, a flashlight capable of condensing light includes a flashlight main body, a lamp seat, a lamp housing set and an optical carrier with high transmittance. The flashlight main body has a battery sleeve for accommodating a battery. The lamp seat is provided for disposing and connecting light emitting elements, and disposed in front of the flashlight main body. The lamp housing set is put to the front of the flashlight main body to protect the lamp seat and the light emitting elements. The characteristic of the flashlight is that: the optical carrier is an optical transparent lens in disk shaped. Two sides of the optical carrier have convex arc surfaces with circular section diameter, so that the circular section diameter of the convex arc surface of the front is bigger and the circular section diameter of the convex arc surface of the rear is smaller. Therefore, the optical carrier capable of condensing light and having transmittance is composed, and disposed and fastened to the lamp housing set for positioning. The lamp housing set is assembled to the front of the flashlight main body together with the optical carrier to enable the optical carrier to be disposed in front of the light emitting elements, thereby assembling the flashlight capable of condensing light.
The optical carrier adopted by the foregoing conventional structure shows the convex arc surfaces at the two sides. The two convex arc surfaces are circular sections. Namely, the conventional lens design applied to the illumination lamps is a sphere surface. When a light source is placed to the focus of an end of the sphere surface, light will be refracted from another end after refracting. A parallel light beam will be theoretically obtained and the minimum emergence angle is taken. However, when a sphere convex lens is practically adopted, the parallel light beam is unable to be acquired completely. The scattered light still appears after refracting the light source.